Reversible die.



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F. 0. WELLS. REVERSIBLE DIE. APPLIOATION FILED AUG. 25; 1913. 1 9 1 133?? y 11; 1133?; M Patented Feb. 23, 1915.

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i sits. aria new NK 0. WELLS, OF GREENFIELD, MASSACHUSETTS, ASSIGNOR TO GREENFIELD TAP dz DIE CORPORATION, OF GREENFIELIB, MASSACHUSETTS, A CORPORATION OF MAS- sacnusnrrs.

REVERSIBLE DIE.

Application filed August 25, 1913. Serial No. 786,471.

To all whom it may concern:

Be it known that I, FRANK O. Wnms, a citizen of the United'States, residing at Greenfield, in the county of Franklin and State of Massachusetts, have invented neware partially formed, and, at their opposite ends, the threads terminate flush with the opposite end of the die. The purpose of the cut away threads is to permit the work to readily enter the die, and, at the opposite end of the die its threads are brought out square to the edge in order to form a full sized thread directly up to a shoulder on a piece of work. a

One of the objects of the invention is to form a thread-cutting tool'that can be used in a screw cutting machine or in an ordinary machinists hand stock.

A further object of the invention is to,

provide a thread-cutting tool in order that only one die may be purchased or carried in stock, thus obviating the necessity of purchasing a duplicate'set of dies when it is desired to cut a thread up close to the shoulder of a piece of work.

Broadly, the invention comprises a pair of oppositely located die elements, or chasers in a collet member, the sides of which are oppositely beveled to form surfaces which are inclined at equal angles 'toth'e axis of the die elements. These die elements are adapted to be rigidly retained in a collet member, a portion of the interior surface of which is formed with inclined surfaces in a recessed portion. These elements are secured in place in the collet member by means of a clamping nut or ring that is screw-threaded into the collet member, its inner face bearing directly against the die elements to force them to their inclined seats in the collet, and its outer face at its opposite side is formed with a projecting hub-portion through which an opening is formed for the purpose of guiding and directing the 'worlr on which a thread is to be cut.

die elementsassembled therein. 2 is a vertical sectional View on the line 2-2 of Fig. 1, showing the entire construction in an assembled position, the collet member and one of the die elements, also illustrating the clamping nut or ring. Fig. 3 is a view of Fig. 1, showing the reverse side and illustrating the clamping nut which retains the die elements in place in the collet. Fig. d is a vertical sectional view on the line 4-4 of the Fig. 1, showing the die elements in section, and their relative location in the collet member, also the set screws for adjusting the die elements toward and from each other for. the purpose of accurately positioning the die elements, in order to cut a thread of the correct diameter. Fig. 5 is a detailed view of the collet member with the clamping nut removed and illustrating the entire construction of the collet member which rigidly holds the die elements in place, also one of the set-screws for adjusting the ,die elements. Figs. 6, 7 and 8 show my new die as applied to other forms of collets.

Referring to the drawings in detail: 1 designates the collet member which is adapted to be clamped in the chuck of a screw cutting machine, or, it may be clamped in an ordinary machinists stock, the ii-shaped recess 2 indicating the means for securing the collet in a machinists stock. One side of the collet member is screw threaded as indicated at 3 for the purpose of receiving the clamping nut or ring 4-. This clamping nut is designed to rigidly secure the die elements 5 in place in the collet.

Referring now to the detail constructionv of the die elements and it will be noticed that these elements. are formed with inclined faces 6 and 7, which are oppositely inclined to the axis of the die element. extend one half of the thickness or length of the die element as indicated at the point 8. K

an equal amount to the axis of the die element as the faces 6 and 7, permit, by reason of this duplicate inclined-planed construction the reversal of the die elements, or in other words the die elements may be changed end for end in the collet member 1.

Referring now to the. collet member 1 and particularly to the interior construction Patented Feb. as, rare;

These faces thereof, it will be noticed that one end of the collet member/ opposite thethreadedend 3 is formed with inclined surfaces 11 and 12 The angle of the inclination of these surfaces is the same as the inclined surfaces 6 and 7 of the die elements 5, as clearly shown in Fig. 2 on the sectional line 22 of Fig. 1, the view being taken as looking from the right or from the. left of this sectional line.

In order to retain the die elements 5 rigidly in place in the collet memben 1, the end 4 is formed with an exterior thread 13 which engages. the thread 3 of collet 1, Y The inner face l4 of the nut 4 engages the inner faces or surfaces ,of thedie-elements 5, as shownin Figs, 2-and 4; whereby whenthe nut,.4 is turned tightly into the collet 1-, the inclined surfaces (Sand 7 of the die elements are vforced firmly against the inclined surfa ces ll and 12. of.thecollet member, thus preventingtheir becoming loosewhen the d eisu'se v In ,.using this tool if it is desired to cut simply a. thread on the end of-a: Piece of work that isof uniformsize, the die elements .5. .are inserted in-the colletl in the position shown in Big. 2, thatis to say,- wit h the cutaway threaded portion 15- engaging the 'work as it is. fedtowand the die. Should it befdesired I to cut a thread up to, or adj acent, a shouldered portion= on i a .piece;:of

7 work, then the die members 5, are placed in the collet.member.1,-,.in the reverse position to that shown in Figs. 2 and 4, that is to say, the full-sized threads 16, at,the-.opposite end of .the ,die$, Wil1 .cut a perfect thread on a piecev ofiworkin which there-is a shoulder en gge the die members 5 as clearly. shown;

formation. means of this -.construction, die elements which-h a ub taper ca -.e =0mp1ish thesame results as; two sets shop .onfactory equipped with this combinaa tion ofdie, canusetha same tqoLfor-two distinct purposea thus sav ng an "expense,

thenecessity-of equipping with two sets of threadrcutting .tools.E Also-by means of'this construction, the. Same collet member can-he used to insert, die ,elements .having threads of different sizes. In: order to adjust the die members toward and from eachgothem-se't screws l l are provided... These set screws 4- a nd tbyrmeaneof a suitable screw these Set-screws can -,he--,r otated to It -willv readilyabe seen that by- .01? dies; and;

chasers having sired. 1

It is to be understood that this die. is so formed that, in operation, when the end of the .stock to be threaded just protrudes above the top face of the die, a thread of standard length has been formed on the stock. P

- The end 4 is formed with an opening therethrou h and in this opening are provided gui e-ways 18 on which rests the Work during the cutting of the thread. It will be seen fromthis construction that I have-produced a. thread-forming tool that is very simple and one that can be readily reversed-as occasion re uires, and one in which thread-formingementsor dies of different diameters may i be readily inserted and removed,.also one that is adapted for use, either in a screw-cutting machine or in a machinists hand stock Y Referrin now to the modification illustrated in Figs. 6, 7-, and 8: In Fig. 6 the collet member comprises a tubular shank portion 20 provided with a head 21 having suitable beveled seats for the dies which are se cured therein by overlying plate 22. In Figs. 7 and 8 the dies. 5- are secured in the collet 30 by means of wedges 31, secured by screws 32, as shown. z

It will be seen therefore, that'while my new dies have been specifically described in, connection withone form of collet, they are by he means restricted for use solely with that form, but may be usedwith any collet.

What I claim is':-:- 1 A'reversible die, comprising a collet member, formed with. upwardly-converging-recusses therein and designed to receive the die chasers,. said die chasers'being formed with threads substantiallythroughout their entireheight, the height of said chasers' be ing substantially equalr tothe length of a standard-r;thread, the side faces of said reversely formed tapered surfaces either-one of which may engage with said irecessesiin the collet member, and a; guide-member adapted to clamp said tapered surfaces in said recesses as de scnbed.

I FRANK 0. WELLS.

Witnesses:

BALL, DANA MALQNE; 

